Sequential tripping mechanism control for multiunit offset presses



Ot.'28, 1952 A. J. ALBRECHT SEQUENTIAL TRIPFING MECHANISM CONTROL FOR MULTIUNIT OFFSET PRESSES 4 Sheets-Sheet 1 Filed Jan. 27, 1948 INVENTOR ALEXANDER J. ALBRECHT TTORN A. J. ALBRECHT Oct. 28, 1952 I SEQUENTIAL TRIPPING MECHANISM CONTROL FOR MULTIUNIT OFFSET PRESSES 4 Sheets-Sheet 2 Filed Jan. 2'7, 1948 FIG. 4

' ALEXANDER J. ALBRECHT BY An-mu 5 Oct. 28, 1952 ALBRECHT 2,615,393

SEQUENTIAL TRIPPING MECHANISM CONTROL FOR MULTIUNIT OFFSET PRESSES Filed Jan. 27, 1948 4 Sheets-Sheet 5 I nllllllllllm 0 u I i A 2% 'I. m I

INVENTOR ALE X'ANDER J. ALBRECHT Oct. 28, 1952 A. J. ALBRECHT 2,615,393

SEQUENTIAL TRIPPING MECHANISM CONTROL FOR MULTIUNIT OFFSET PRESSES Filed Jan. 27, 1948 4 Sheets-Sheet 4 zzv F IG. 8

INVENTOR ALEXANDER J ALBRECHT BY V ATTORNE 5 Patented Oct. 28, 1952 UNITED STATES SEQUENTIAL TRIPPING MEGHA'NISM-CON TRO-L FORlVIULTIUNIT OFFSET PRESSES Alexander J'. Albrecht, WestNew-Yprk, N..J,., as-

signor to R. Hoe & 00., 1110., New York, N. Y., a corporation of New York. v

Application January 27, 1948, Serial No.4;650

8 Claims. 1. This invention relates to printing machines and more particularly to-tripping mechanisms for rotary offset presses.

Rotary offset printing units as heretofore construc-ted, embody tripping mechanisms which are designed to trip the various elements of the unit on and ofi in a definite order and at definite times in the unit operating cycle, so that the various parts may be properly inked for applying ink to the paper and will not set off the ink or smudge the image during an operating cycle when no paper is in the unit. Such operating cycle, unless interfered with manually, has been fixed. The operating cycle, however, has been selected primarily with reference to the machine operation whenprinting a sheet during each op-- erating cycle, the tripping mechanism providing for. throwing the unit temporarily out of operation when a sheet is missed. A proper operating cycle for a unit when operating continuously, or substantiallycontinuously, may not be by any means the ideal cycle for use in starting up a machine which has been out of operation for any considerable time. For example, it sometimes occurs in starting up an offset press that the paper, will stick to the blanket cylinder and may tear and wrap on the blanket, necessitating suspension of printing while the-paper is cleared out of the unit, and sometimes denting the blanket so as ton'ecessitate replacement or repair and even in some cases damaging'the plate. By running the plate cylinder against the blanket in advance of the time when printing by the unit is commenced, this tendency of the paper to stick to the blanket may be eliminated or very largely reduced. This effect. appears to be due to the moistening of the blanket by the plate cylinder and may also be due to the-working of the ink on the blanket cylinder.

It is an object of the present invention to provide for automatic premature tripping on of plate cylinders;

A further object of the invention is to. provide tripping mechanisms and controls which provide for premature tripping on of plate cylinders, where necessary, without interfering-with normal unit tripping cycles.

It is also an object of the invention to provide an improved unit tripping mechanism.

Still another object of the invention isto provide a trip control for multicolor ofiset presses including provision for sequential tripping. of the units.

With these and other objects which will appear in the'following description in mind, the inven- 2 tion consists in the combinations and arrangements of parts and details of construction, and the, method of tripping, which will now first" be fully described with reference to the accompanying drawing and will then be, more particularly pointed out in the appended claims.

In the drawings: I .7 Figure 1 is a schematic end elevation showing a'blanket cylinder and associated plate cylinder.

together with certain tripping mechanism;

Figure 2 is a similar view showing theblanket cylinder and associated impression-cylinder;

Figure 3. is a fragmentary. schematic view showing the blanket and plate cylindersandcertain ink motion elements associated with the latter;

Figure 4 is a view showing the trippingcontrol mechanism of the invention, as associated with a typical unit;

Figure 5 is a view similar to Figure 4 but showing the parts inadifierent operating position;

Figure 6 is a'view showing a plate cylinder and associated unit tripping mechanism embodying theinventionin amodifiedform; v

, Figure 7 is a. circuit diagram showing. thedmanner of incorporating the mechanism of Figure 6 in a multicolor press, together with additional control elements for a multicolor offset press; and

Figure 8-is a circuitdiagram showing still another modified form of the invention.

In Figures. 1 t 5 the invention is shown as applied to. an offset press having printing. unit tripping mechanism generally of the 'type shown in Horton and Eckhard Patent No: $419,403, granted, April 22-, 1947 for Printing. Machines. Only 'so much of the old andflknown tripping mechanism is shown in the drawing as is neces-,

offset printing unit are; shown. Figure 15 shows the plate cylinder l and blanket. cylinder 2rtogether with associated tripping mechanisms. Figure 2 shows the same blanketcylinder 2 and the impression cylinder 3 with otherl tripping mechanism, certain parts shown in' Figure I being omitted for clearness in the" drawing,

and Figure 3 shows the plate cylinder I and blanket cylinder 2 together with part of the ink motionand tripping mechanism therefor; certain parts shown in Figures 1 and'2- being-,again, omitted. In thestype of unit-shown, the-cylinders tour of cam 21.

are separated or tripped off by eccentric bearmounted on shaft 22 and. which carries a cam follower roller 32, which is urged against the cam 6 previously referred to by a spring 33. The plate 30 thus rocks back and forth during each rotation of the blanket cylinder and in so doing reciprocates a bar 34 having upper and lower of movement of an actuating mechanism for 1 tripping the cylinders on and off, and the press control mechanism and a timing mechanism rotated with the blanket cylinder determine whether the actuating mechanism causes the unit to trip on or off and determine the time when this action occurs.

The impression cylinder tripping mechanism is shown in Figure 2. The actuating mechanism I comprises a cam 6 rotating with the blanket cylinder and upon which rides a cam follower roller 1 'at one end of an arm 8 which is pivotally mounted at 9. An operating bar It is pivotally connected to the arm 8 at I l and a spring [2 serves to hold the cam follower roller '5 against the cam B. Each rotation of the blanket cylinder, accordingly, causes a reciprocation of the bar l0. The bar 10 carries an upper abutment i3 and lower abutment M for engaging upper and lower studs l5 and 16 carried on a plate mounted on the impression trip shaft ii. If the bar I!) is held up. abutment I3 will engage the stud l5, rocking the shaft l7 clockwise, while if the bar [0 is held down its abutment I 4 will engage the lower stud l6, rocking the impression trip shaft [1 in the counterclockwise direction. Shaft I1 is connected by means of an arm 18 and link I9 with the arm 4 which rocks the cocentric bearing for the impression cylinder and the parts are so arranged that the impression cylinder will be tripped on when shaft I? is rocked counter-clockwise, or into the position shown in the figure, and will be tripped off if the impression cylinder trip shaft is rocked clockwise.

The direction in which the bar i0 tends to rock shaft [1 is controlled by a link 20 connected to an' arm of a Y-shaped member 2! pivotally mounted at 22. A second arm of member 2i terminates in a toe-23 which engages in a notch at the end of a catch 24 laterdescribed in detail. So long as the catch is in its upper position or the position of Figure 2, the Y-shaped member 2| is held from counterclockwise movement and the bar I0 is permitted to assume its lower position, or the position of the figure, so that the impression will be tripped on and remain tripped on. When the unit is to be tripped off, the catch 24 is dropped by mechanism later described, and spring 25 forces the Y-shaped member 2! counterclockwise so as to lift the rod 53 by means of the link 20. ment occurs is. controlled by means of'a cam follower roller 26 carried on a third arm of the Y-shaped member 2! and cooperating with a cam 21 which rotates with the blanket cylinder. In the normal operating cycle the catch 24 will be operated while the high part of cam 21 is under the follower roller ,26 and the arm H1 will thereafter be lifted at the proper point in the unit operating cycle, as determined by the con- The operating mechanism for tripping the plate cylinder (Fig. 1 is generally similar to that just described and includes a plate 30 pivotally The time at which this move-' abutments 35 and 33, which cooperate with upper and lower studs 3i and 38 on a plate fastened to the plate cylinder trip shaft 39. Shaft 39 is connected to arm 5 which rotates the plate cylinder eccentric bearing by means of an arm 40 and link 4!.

With the parts in the position shown in Figure 1, the lower abutment 35 of the bar 34 is in position to engage the lower stud 38 for rotating the shaft 39 counterclockwise and tripping the plate cylinder on. Lifting the left hand end of this bar will bring the upper abutment 35 into position to engage stud 31 for rotating the plate cylinder trip shaft 39 clockwise and tripping the plate cylinder off. This lifting movement is accomplished through rod 55 by a bell crank 43 pivotally mounted on the shaft 9. The other arm of the bell crank is pivotally connected. to a link Q'iwhich in turn is pivotally connected to an'arm 43 fixed to the impression cylinder trip shaft H. Clockwise rotation of the impression cylinder trip shaft ll will thus tend to rock the bell crank clockwise, lifting the bar 33 for tripping off the plate cylinder.

The ink motion tripping mechanism is also operated from the impression cylinder trip shaft 1 by means of arm 50 (Figure 3) and link 5! operating on an eccentric plate 54. Rotation of this plate in one direction will bring the ink motion from rollers 52 into contact with the plate cylinder and rotation in the other directionwill separate these form rollers from the plate cylinder, thus tripping off the ink motion.

A spring 53 operating on an arm fastened to the plate cylinder trip shaft 39 serves to hold this shaft in tripping on or tripping off position, as the case may be, until moved into the alternative position by operation of the bar 34 on stud 37 or 38. Similar means, not shown, and which is well understood in the art, is provided forthe impression cylinder trip shaft El.

Means may also be provided for locking one or more of the elements in tripped on or tripped off position. Such means, however, 'are well knownin the art and are fully disclosed in the Horton and Eckhard patent above referred to and will not be described herein since they form no part of the present invention.

A number of units such as the unit shown schematically in Figures 1 to 3, may be combined into a multicolor offset printing press, suitable means for conveying sheets to be printed from oneunit to the next so as to superpose the different color images in registry being provided. A variety of such means are available but it will be assumed by way of example and for simplicity that the units are incorporated in a press of the chain conveyortype such as shown and described unit along the path indicated generallyby-the broken: arrow (Fig; 2) it will engage a-shoe-56 pivotally' mounted at 51;, rocking" theshoe- 56 clockwise; Thejclockwise rocking of shoe 5'6 operatesthroughlink- 5'8 totrip the catch24 previously referred to. As shown more clearly in Figures -4-and.5, thecatch is carried ona-pivot 59 and hastattachedttoit anarm 6.0. carrying a pin Bl which is located within a slot formed at the upper. endiin. the link 58: The clockwise rocking: of shoe. 5.6.: by the. gripper bar trip .1 control roller 55. will. accordingly. rock thearm 60 andi catch. 241 counterclockwise',v dropping: the catch: 24 below the-toe: 23; of: the v shaped' trip control 1 member; 2| and: permitting. this member to initiate .thertrippingoffi cycle of; the unit: under timing contro'lzby. the camlfh. The catchM-i'carries a. projection; 65; adaptedtor. engage: under a hook formedtonaa.pivotedizlatch;membenfifii The latch member 86: is: urged; counterclockwise by spring means. (not: shown) andlwill accordingly hold the catch" 24"" down even aftervthev shoe 56 has returned to the position: of Figure 2 -following passage optrippingzcontrol. roller 55.1. The toe 23 of the lower: arm ofzthe: Yr-shapedmember 2 I will accordingly be"; free. to: move. when. permitted to do so. by: cam 212. Further. movement of the Y- shaped member, pastthe position indicated in phantom in Figure 5', will. engage the; curved upper end of the latch. 66; .thus. freeing thecatch 2 4 permitting: the. notch: at the. end thereof 1' to catch the toe 23- upon the return. movement of member 21 which is caused by: cam. 2'5 upon further: rotation of: the blanket: cylinder;

The tripping'mechanisme as thus. far described" is wellknown and fullydescribed in the Horton et-al! and Huck patents. referred to ab0ve,,and has. been described herein merely for a more complete understanding 1 of the present: invention which isconcerned with. provision for: sequential? tripping for a number of: units,. provision for modification-of the sequentialtripping cycle to trip certain platecylinderson prematurely and with other objects which will appear from. the following description;

Normal? u'mt tripping'cycle In an offset press. unit: as justdescribed, the printing involves the application. of. ink to the plate cylinder and. the. transfer-of inkfrom the platecylinder to the blanket; cylinder and from theblanketcylinder to the sheet passingv between theblanket cylinder. and the impression cylinder. The cams 6 and 2? are so designed in relation tothezpositioning ofthe cylinders that the press-elements will trip; on and'ofi at proper points. Assuming the unit. to be-in operation for printing upon a sheet; a. printed: image-will be transferred from the. blanket. cylinder. 2:.to;the paper: at each rotation thereof... Meanwhile, the ink motion: will.be'inking the plate. cylinder Iv in preparationiior the. next. printing; so;-that a part of this: ink image-toibeprinted: on the next sheet will. have: been transferred to the blanket: cylinder in preparationior'the next sheet. The tripping-off of the impression will. betimed. so as to occur while the gap in: the: blanket is opposite the impression cylinder: At'this time theimage on the plate which isto. be applied to thenext sheet will have'been inked so that the ink motion I is tripped off at the same time as'the impression.

The plate'is allowed to-run in-contact with the blanket, however; until the remainder of the ink image. for. the. next sheet has been transferred to the blanket cylinder, at which time; while the 6 gap in the'blanket' cylinder is opposite vthenplate cylinder, the plate cylinder is tripped. off. The blanketinv a tripped offf'unitzaccordingly holds the inkto be applied'tothe next sheet which. 1573C- cepted; When the unitisagaintripped; on, the blanket and impression cylinders are brought together while. the gap on. the blanket cylinder is opposite the impression cylinder so that theink image on theblanket may be transferred to the sheet: Simultaneously theinkmotion is tripped onto theplate cylinder for'inking another image which. will be: applied to a second; sheet. The

plate; cylinder; however; is not tripped, onto the; blanket. cylinder untillthe'gap in the:blanket cylinder; is. opposite. the. plate cylinder; so that the blanket: cylinder has: a complete inkimage appliedzto it foreac-h sheet to be printed-and no part of this image is inked double. These-cycles of the relative movements of the cylinders and the ink motion may becharacterized as the operating cycles of the unit for tripping 01f and tripping on The. corresponding actions. of different. units may, occur. simultaneously or: some units may. be in. advance of other units. If the sheet carrying devices travel at a constant speed such that the leading. edgeof the sheet, moves ataspeed equal to the peripheral. speed of the impression cylinders. and-thev length of'its. path of travelbetween units is equal: to,v or. is an, exact multiple of, an

' that the unitcams 6" ancillj'may be varied somewhat so. long as the. tripping on and'oiT of'the various elements occurs within the, limitsof' the gap in..the blanket cylinder. In certain cases the units may be deliberately putout ofiphase, For example, ina chain. conveyor press a proper spacing. of gripper. bars and balancin'gof'. the chain may. require, that the path. of travel of the sheet between units exceed slightlythe impression cylinder circumference, so that,v each, unitwill la behind its preceding; unit bya smallv angle.v

When the. press is put into operation, starting with. all units tripped-off; thefirst unit will be trippedon as a gripper bar'carr-ying an accepted sheet approaches. lT-he second unit'will, however, remain tripped off. until the sheet has passed through the, first unit and. the gripper bar-is approaching the second-unit. This will normally of a unit may'not trip on at the sametime-as the plate cylinder of a previous unit.

While the invention is disclosed herein for definiteness as applied to an=offset printing press in which the-separation of; the impression and blanket cylinders is accomplished by moving the impression cylinder, it will be apparent that it is also applicable to machinesin whichthe blanket cylinder is moved awayfromthe impression cylinder. Accordingly, when the tripping oncr off of the impression is referred to, it is intended --to include either of these actions. Similarly the invention has been disclosed, for definiteness, with reference to a press in which the separation of the platecylinder and blanket cylinder is accomplished by moving theformer. Theinvention is also applicable to offset presses in which the separation is accomplished by moving the blanket cylinder away from the plate cylinder, either of these two types of action being contemplated when reference is made to tripping on or off of the plate. The tripping on or off of the ink motion is ordinarily accomplished by moving the form rollers away from the plate cylinder but could also be accomplished by moving the plate cylinder away from the ink motion, should this become desirable. Either type of action is contemplated when reference is made tothe tripping on or off of the ink motion.

Printing unit premature plate cylinder tripping mechanism unit in which the order of events is not varied unless manually interfered with by the operator. According to the present invention, the link 47 is jointed to make provision for tripping the plate cylinder on in a given printing cycle of the unit, even though the impression cylinder may be tripped off, and a control mechanism for regulating the action of th links M in the various units is provided.

As shown most clearly in Figures 4 and 5, the link t! comprises two sections iii and H joined by a hinge T2. The hinge opens downwardly as indicatedin phantom in Figure 5, but hinging in the opposite direction is prevented by a stop 73, as indicated. The section 1] of the link 41 is formed with a T-head'at its right end, having an upper arm or horn T5 for engaging a stop 16 and a lower arm or horn H, which is curved as indicated and adapted to engage a pin 18 carried on a sleeve 79. The movements of sleeve F9 are regulated by mechanism described below.

If the sleeve is in a rightward position as indicated in Figure 4 and the impression is tripped off by rotation clockwise of the impression cylinder trip shaft H from the position of the figure to that of Figure 5, the link ll will be forced to the left for tripping off the plate cylinder. It will be observed that the turning moment of the link section ii about the hinge 72 which is thus created is counterclockwise. Since such counterclockwise turningis prevented by the hinge stop 73 the link i? will act as a rigid link and will rock the bell crank 48 so as to set the plate cylinder tripping mechanism for tripping on. If, however, the sleeve 19 is moved to the left so that the pin '18 occupies the dotted line position of Figure 5, it will engage the lower arm or horn ll of the'T-head on the link section II, rotating this section so as to break the hinge 12. With the hinge broken, as indicated in phantom in Figure 5, clockwise rotation of the impression cylinder trip shaft ll into the position of Figure 5 will result merely in bending the link 7 47 about its hinge 12 so that the plate cylinder tripping mechanism will not be set to trip ofi. Should the impression cylinder trip shaft be al-- ready set to tripping off position and the link 41 be straight (solid line position of Figure 5), movement of the sleeve E9 to the left will,

wise and position the plate cylinder tripping mechanism for tripping on (phantom position of Figure 5).

Unit control mechanism for the premature plate cylinder tripping mechanism Means as shown in Figures 1, 2, 4 and 5 are provided for controlling properly the movements of the sleeves l9 associated with the various units so as to obtain the desired action. These means comprise for the registering unit and each printing unit a slide bar 96, 99A, tliB etc., as the case may be, suitably carried in members attached to the frame of the machine. For understanding the action, Figures 4 and 5 may be considered as representing two successive units of a multicolor press and for definiteness the first and second units thereof, Figure 5 representing the first unit, and Figure 4 the second. The bar 98A extends between the first and second units and bar 9E5 extends between the second and third units and this arrangement may be reduplicated indefinitely according to the number of units in the press. At the feeding end of the press, ahead of the first unit, is a similar bar 98 extending from the registering mechanism to'the first unit. It will be observed that all these bars are in alignment so that forcing bar 99 to the left will move all the bars A, 9013 etc. to the left. Similarly, moving any bar associated with a unit, such as the bar 99A, to the left, will move the bars associated with later units. Each bar is urged toward the right'by a spring 9!, 91A etc. acting against a frame member 92, 92A etc. and against a washer 93, 93A, etc. attached to the bar. These springs serve to hold any bar and all bars ahead of it in the sequence, which are not otherwise held in a leftward position, in a rightward position, or the solid line position of the figures. Each bar 99, 90A etc. carries one of the sleeves 79, each sleeve 19 being urged against the corresponding washer 93, 93A, etc. by a spring 9 94A etc. acting against a washer 95, 95A etc. attached to the bar in question. Each sleeve 79 is accordingly normally held in a leftward position on its bar 90, 90A, etc., as the case may be, against the Washer 93, 93A etc., but may be forced backwardly or to the right on the bar, such movement being opposed by the associated spring 9t, 94A, etc.

A dog 96 pivoted at 9? (Figure 4) and urged counterclockwise by spring 93 is provided for each unit and carries a lower hook 99 in position for engaging ina notch lilo formed in the corresponding sleeve 79. The dog 96 also carries an upper hook HM adapted for engagement by a hook I02, pivotally mounted at H33 on the stud plate of the corresponding impression cylinder trip shaft H and urged clockwise by a spring H34. If the impression cylinder for any unit is tripped on so that its trip shaft I7 is in the position of Figure 4, it will be observed that the corresponding sleeve it will be held in a rightward position by the dog 95 associated therewith, since as soon as thesleeve starts to moveto the left, hook 953 will fall into notch I00. Thus, even though rod 98 and all the other rods 50A etc. may be moved to the left, the tripping cycle of the unit in question will not be affected, but the link i'l thereof will act as a rigid link. The sleeve 19 associated with other in.Figure.5,hook I02 engaging underhook IM will holdup the dog .9.6.so that the associated sleeve 19 is free tomove to the left under control ofthe bars- 90, 90A, etc.

Operationofunit p rematureplate cylinder trippingmechdm'sm A number of actions may be obtained, depending uponthe sequence of movement of the various partsjust described and for affull understanding of the present invention it is necessary to review the possible actions obtainable in a given unit, depending ,on the position and order :of movement of the parts. For .this purpose the unit depicted .in Figure 5 may be .selected as illustrative. It may ..be assumed, in the first instance, that-thebariSIJ is in the. right hand position,. and .that the variousparts .are in thefull line positionof the figure. fIt willbe apparent that=both the impression cylinder and the plate cylinderare .set to .trip off during the operating cycle of the unit in .question. If the next tripping control element "55 (Figure 2) .to arrive at the .unit .is-set .to ,trip the unit off, it will trip the .catch.24, setting the .unit tripcontrol mechanismfortrippingoff, inadvance .of .the time when .the bars JIII and 334 make the operative parts oftheir strokes, so that the parts .willremain-in thecondition of the figure. vShould the control element-55 associatedwiththe next gripper bar beset. to tripping on position, it will fail to engage. the .shoefl56, .with the result that the. impressioncylinder trip. shaftltl .will rotate counterolockwise intotheposition of Figure 4,-.trip pingon thelimpression cylinder, and in. so doing will rotate thev bell crank .45 ..counterclockwise for also tripping on the plate. cylinder. .As the impression cylinder .trip shaft-I1 rotates, .hook I02 wilLdisengage from hook .IIlI, thusfreeing the. dog.-96 as shown inFigure 4 and preventing leftward -movement of the sleeve 19 associated withthis unit should the bar-90 laterbemoved to the left.

.Starting again withthepartsin the .full line position of Figure 5,v it may be assumed-that prior to the-arrivalof the next tripping control ele- 11181113455 the: bar 90 has been moved .tothe left (dotted 'line .position of .the figure). In this case,-the-sleeve 19, beingfree to move,.will move with the bar and will breakthehinge I2 of "the link 41, moving this link into the phantom position of the figure and setting-the plate cylinder of the .unitin question to tripon. This-motion of the sleeve will carrynotch Illupast-the-hook 99 on the dog 96, thus preventing thehook 99 from falling into the notch I100 until the-sleeve has been forced backto the right. Theparts will remain in this-position until a tripping control e1ement-55 which is set in the tripping on position, arrives at the unit. Thereafter, at the proper time in the operation'cycle of the unit, the impression cylinder will trip on, the impression cylinder trip shaft rotating counterclockwise into the .position of 'Figure 4. :This

. 10 will engage the upper arm 15 of the: link section 'II against stop .16, straightening out the 'link 41 and forcing 'the'sleeve "I9 -backwardly toward the position shown "full lines in Figure -4 so that the ho ok;9.9 may engage in notch I01] and hold the s'leeve'in its rightwardzpositionuntil the unitin question'isagain tripped oif. -The'plate cylinder will remain "tripped "on. "If, while-the parts are inlthis position,"the impression is again tripped off, jhook 1'92 will not engage under hook IUI of .the dog 96 by reason iof the fact that the seating of the'lower hook I02 in notch I00 of "the sleeve glowersithe ,hook I III sufficiently 950 that hook I02 clears it.

'Theforegoing description covers the operation of 'the elements under 'various possible assumption's starting with *theparts in the full line positionofl'qigure5 anditwill-bemotedthat so long as the associatedcontrol .bar 90, "A, etc. 1 is in. a leftward position, i the plate 'cyli-n'der tripping mechanism will be held -to the'tripping on position. even though the' imp-ressionisjtripped off, but that as-soon 'asthe impression cylinder of itheunit'ti'ips on the sleeve 1 9 .will "be held in a rightward or inoperative position until-such time as theficontrol bar90.is again moved.

"Starting with the parts .in the full line position of'.Figure l, which corresponds to'the tripping on oftheunit, it willbe seen that thesleeve I'Qis at all times held1in a rightward position so that the "link 41 is not broken and the' plate cylinder tripping cycle follows the control .of'the impression cylinder tripping shaft II.

Control 07 premature plate cylinder dripping Thy th'e registering unit :The desired trippingcyclefor the'various units may be obtainedz byrmoving the barsrQ-O, EDA-etc. in the following :way: The extreme right hand endrof bar -90 =(Figures land '2) carries ,arbar II 0,-which: is pi-votally attached to the bar 7.96 :at I II F and :the under side of which i is rformed I with accutoutl t2 engaging pin I-I3attheupper end of1-an arm II4, which ,--is-fastened to the sheet stripping shaft :I: I5 associated with the registeringrunit. This.shaft carries strippers ild-and operates: in a manner described more fullyin-the Huck'patentaboveref-erred to. :For purposes of the;;present;invention,. however,- the precise? mode of operation .of -the stripping shaft 1H5 :15 "not important as it will be apparent'that any element-mov-able-f-rom one :position to anotheraccording to whether asheet-is rejected. oraccepted could be. substituted therefor and-would operate in the same way with the mechanism :of the present invention. -With the:parts;in the full line. position of :Figure I 1, and in which! theyposition "of the shaft I- I5; and elements carried thereby corresponds to the position occupied when-,;a sheets-has: been reiectedxthe spring 5 9 I gassociated with-bar-.=-9,0 is permitted-to force the;: bar into its rightward position in which :the 'sleeve "I-EI carried thereby will .not cause the trippingeon of :the" plate oylinderr mechanism. The, same will be true. of all the otherj bars 80A, B --etc.-,unless held in a: leftward :position by other: mechanism laterzdescribed. 51f, however, .a .sheetisaccepted, the strippingshaft I :will rock in.aco;unterclockwise direction.into:the dotted line-position ofFigure 1, thus forcingbars 90, :90 A,;:90B..etc. toathe left :so that the premature. tripping on. of the;platev cylinders prior to the timewhensthe impression. cylindersare tripped on is obtained.

v.It. may be. assumed, inv the-first. instance, I that ll the press is out of operation, which implies that empty gripper bars have passed through all units and have tripped these units off. The mechanism at each unit will be in the full line position of Figure 5, the hooks I! and I02 at each unit having been caused to engage, as shown by reason of the rightward or clockwise movement of the arm IN and hence of the bars 90, 90A etc. As soon as a sheet is accepted, the arm II 4 will swing counterclockwise into the dotted line position of Figur 1, and will hold all the bars 90, 90A, (Figure and 9613 (Figure 4), in their leftward positions. All sleeves I9 will also move to the left, breaking the links 47 as indicated in phantom in Figure 5. All of the plate cylinders will now trip on under control of the cams 6. When the gripper carrying the properly registered sheet arrives at the first unit, the impression cylinder for that unit trips on by reason of the fact that the control element 55 associated with this gripper bar fails to operate the shoe 56. The impression cylinder of each succeeding unit likewise trips on one cycle later than the immediately preceding unit. The result is that the first unit in line will have its plate cylinder tripped on one cycle early or before the cycle in which its impression cylinder is tripped on, while the second unit in line will have its plate cylinder tripped on two cycles early, and the plate cylinder of each succeeding unit will be tripped on prematurely during an additional cycle. If it is desired to silence the premature tripping control from the registering unit, this may be done by means of a hand lever I20. Swinging this lever from the full line position of Figures 1 and 2 into the dotted line position of Figure 2 lifts the bar I I0 into the dotted line position of the latter Figure, so that the bar H0 is lifted clear of the pin H3 and the spring 94 associated with rod 90 is permitted to hold it in its rightward position.

In some multicolor rotary offset machines,it is found desirable to permit the machine to run following the rejection of a sheet, the successive units tripping off sequentially as the empty gripper bar corresponding to the rejected sheet passes through them, then tripping on again as soon as a gripper bar containing an accepted sheet approaches. The invention, while applicable to such machines, is shown as applied to a machine in which once a sheet is rejected, all succeeding sheets are rejected until the mechanism is reset. This action is provided for by a latch I2I cooperating with an inner pin I22 on the arm H4 previously referred to. Whenever the stripper shaft II5 rotates clockwise into the full line position of Figures 1 and 2, the pin I22 will be caught by the latch I2 I, holding the shaft H5 and parts carried thereby in this position until the latch I2I is lifted manually, again permitting the shaft to move counterclockwise into the position for accepting sheets. In such a machine, when a sheet is rejected, the first unit will trip off and remain tripped off and will be followed in order by the second and succeeding units, so that the units of the press will progressively go out of operation and remain out of operation until the-latch I2I is lifted by the operator. In this type of machine, as soon as a sheet has been rejected, all the bars 80, 90A etc. will move to the right, and will remain to the right, as also will the sleeves carried thereby so that as each impression cylinder trip shaft Il' rotates clock wise into the tripping off position, the hook I02 associated therewith will engage under and hold the hook IIlI as indicated in Figure 5.

Control of the premature plate cylinder tripping by a printing unit Means is'also provided at each printing unit for controlling the operating bars 90A, 9013 etc., as the case may be, for all later units. This mechanism comprises for each unit a bar I25 having a cutout I20 adapted to fit over a pin IZ'I carriedon the impression trip shaft stud plate. The leftward end of this bar is pivotally connected at I28 to the upper end of a lever I29 which is pivotally mounted at I30 and the lower" I end of which is formed as a fork surrounding a pin ISI on the operating rod for the next unit. In the case of the unit shown in Figure 4, this is the operating rod 9013, while in the unit shown in Figure 5, it is the rod 90A.

The bar I25 may be set into an operating or V non-operating position by means of handle I32 figure resting on pin I2I within the cutout I26.

The associated impression cylinder trip shaft I'I, if rotated to the tripping on position or position of Figure 4 with pin I21 engaging against one end wall of-the cutout I28 will pull the bar I25 to the right, thus rocking lever I29 clockwise into the phantom position of Figure 4 and forcing rod 90B and any later rods 900 etc. to the left.

By suitably setting the handle I20 at the registering'unit and the various handles I32 at the printing units, premature tripping of the plate cylinders may be varied as desired.

With handle I20 at the registering unit set in its lower or on position and with the handles I32 at the printing units all set in their upper 3 or off positions, the premature tripping of the units will be controlled by the registering unit as previously described. r I

If handle I20 and all the handles I32 are set in the off position, there will be no premature tripping of any plate cylinders and the operation of the press units will be according to the normal tripping on and tripping oif cycles as disclosed in the Horton et a1. and Huck patents above referred to.

If handle I32 for the first unit isset in the on position, while handle I20 and the remaining handles I32 are set in the off position, the bar 90 will remain in its rightward I position at all times and the tripping cycle of the first unit will be normal. first unit impression trips on, the bar A will move to the left, also moving bars 993 etc. The plate cylinders of the second and later units will now trip on. Thus, the second unit plate cylinder will trip on one cycle early, the third unit two cycles early, etc.

Similarly, handle I32 in the second unit may be set on and the handle I26 and all other handles I32 setoif, in which case the tripping on of the first and second units will be normal while the plate cylinders of later units will be tripped on prematurely.

Emergency trip Means is provided for tripping off all units, as may be required in the case of emergency.

As soon as the This means comprises a rod I40 slidably-mounted and extending the length of the machine. The rod is urged to the left by means of springs I4I- but may be moved toward the right by a hand lever I42 (Figure l), on the register unit. The rod carries, for, each printing unit, a stud I43 (Figure 4), which is received within a fork I44 formed on armlill attached to the trip control catch 24- of the unit. Fork I44 is wide enough so as not to interfere with the normal operation of the machine. I-Iowever, when the rod I49 moves to the right, the pins I43, through forks I44, will rotate the catches 24 counterclockwise, dropping'themso as to set all units to trip off during the same cycle. Hand lever I42 may thus be used for emergency tripping off of all units.

Silencing mechanism for the premature trip controls Means is also provided for silencing the premature tripping mechanism for any unit, whenever desired, and comprises an arm I50"(Figure 4), which is loose on the shaft II and has a fork at its upper end engaging aroundv a pin I52 carried on the sleeve 19. The arm I51) normally moves idly back and forth (full and phantom lines in Figure 5) but may be locked in a clockwise position (Figure 4) by turning a handle I53 from the full line position of Figure 4. to the phantom position of that figure. It will be apparent, that this will hold the associated sleeve I9- in a. rightward position, thus silencing the premature plate cylinder tripping mechanism of the unit in question.

By suitably combining the settings of handles I53 and the setting of handles I20 and I32, additional combinations of normal tripping cycles and premature plate cylinder trippings for the various units may be obtained. For example, if the handle I29 is set on, all handles I32 are set off and the premature plate tripping mechanism for the second unit is silenced by means of its handle I53, the second unit of the press will follow its normal tripping cycle and its plate cylinder will not trip on prematurely. The plate cylinder of the first unit will, however, trip on one cycle in advance, while that of the third unit will trip on three cycles early, etc.

While it will ordinarily not be necessary to provide for such action, the silencing by handle I53 may be utilized to provide for premature tripping onof the plate cylinder of one unit and not ofa later unit.

Reverse trip 0 mechanism It is desirable to trip off all units automatically when the press drive is reversed. For this purpose a pawl I68 (Figure 4) mounted on a pivot I6I which rotates with the blanket cylinder 2, is provided. The pawl is urged clockwise by a spring I62 which normally holds it against a stop I63. A bell crank I64 mounted on a stationary pivot I65 carries a roller I66 in position for cooperation'with the pawl I60 and the other arm of'the bell crank is connected through a link 161' and lost motion connection to an arm I68 which is fastened to the latch 24-. So long as the press is operated in the forward direction, so that the blanket cylinder is rotated in the direction of the arrow of Figure 4, the pawl I50 will be pressed idly inward each time it passes the roller I66 and no movement of latch 24 will be produced. If, however, the unit is reversed, pawl I( i0 will engage roller I66, rotating the bell crank I64 clockwise and thus through 14 the link I6! dropping the catch 24 so as to set the unit for tripping off. By this means provision is made for tripping off all units during the same cycle whenever the press drive is reversed.

The modified arrangement of Figures 6 and 7 In the embodiment of Figures 6 and 7, the unit tripping mechanism is modified and an electric control circuit is provided which may be operated by a rotary sequential trip controller such as shown in the Horton and Eckhard Patent No. 2,419,403. Figure 6 shows'the blanket cylinder 2, it being understood that the plate cylinder, impression cylinder and other mechanism apart from the tripping controls may be the same as in the unit described in connection with Figures l to 5. Parts in Figure 6 which correspond to those already described in connection with Figures 1 t 5 are identified by the same reference numerals and further description thereof is unnecessary. It will be observed that the impression cylinder trip shaft and the control of .the tripping thereof by the cams 6 and 21 are the same as previously discussed, the impression cylinder tripping being controlled by a bell crank catch 2B0 pivoted at 2Il| and of somewhat differ-' ent form than the catch 24 previously discussed. It will be understood that the mechanism operated by shaft H for tripping off the impression cylinder and for tripping off the ink motion may be the same as that shown in Figures 1.to 5.

The plate cylinder trip shaft 39 and the parts operated thereby are the same as those in the embodiment of Figures 1 to 5, and a bar 262 having upper and lower abutments 283 and 2&4 operates in the same way as the bar 34 previously discussed. The raising and lowering of this bar when tripping off and tripping on is, however, accomplished in a different manner, a separate control member not operated by the impression cylinder trip shaft being provided. This member is a Y-shaped member 28%; similar to the Y- shaped member M which controls the impression cylinder tripping mechanism and is rotatable on the shaft 4, being urged clockwise so as to bring its cam follower roller against the cam 21. Its lower arm or leg terminates in a toe 2B6 engaging in a notch at the end of one arm of a bell crank catch 287! which is pivotally mounted at 208.

The impression cylinder latch 2% is operated by means of a solenoid 2H If this solenoid is energized the latch 2M will be rotated counterclockwise so that the toe 23 on the lower arm of the Y-shaped impression trip control member 2I is released and this member is free to rotate counterclockwise under control of the cam 21 so as to cause the impression cylinder to trip off. The latch 20% is formed with a projection or hook 2II facing the toe 23 which serves to prevent accidental operation of the impression cylinder tripping mechanism at an improper point in the cycle. If the cam 27 is in the position of Figure 4, spring 25 will urge the toe 23 under the hook -2 I I, thus preventing solenoid 2 I El from'rotating the catch 280. This prevents damage to the operating. parts which might result if the cam follower roller 26 of the Y-shapedmemher were slammed down against .the low dwell of cam2l by the spring 25. If, however, the high dwell of cam 21 is under the follower roller on permitting solenoid2 I 0 to-operate the catch 2%,;

Eckhard patent.

thus causing the tripping off of the impression at the proper time.

The solenoid 22E! operates the plate cylinder trip control latch 2G! in a similar way. The latch 26! has a hook 22! similar to the hook Rid of the latch and is also provided with a projection 222 for engagement under a catch 223. Projection 222 and catch 223 operate in a similar manner to projection 65 and catch 66 on the latch previously discussed in connection with Figures 1 to 3, so as to permit the plate cylinder tripping mechanism to operate under control of the cam 21 even though solenoid 229 may have 7 in a multicolor offset press, controls for each unit being enclosed in rectangles marked out in phantom lines and the successive units being identified by numerals I, II and III. A fourth unit IV and any number of succeeding units desired may be added in a manner which will be apparent when the circuit has been explained.

The solenoids 2H3 of the units are controlled by relays A, A etc. One end of the winding of each solenoid 2m is connected to power line L and the energizing of the associated relay A, A etc. will close its contacts, establishing connection of the other end of the solenoid winding to power line L thus energizing the associated impression trip solenoid 2m.

The plate cylinder trip solenoids 220 are controlled in a similar way by relays B, B etc.

Each of relays A, etc., 3., etc., has one end of its winding connected to power line L. The other ends of the windings of relays A etc. are con nected to three-way switches 23!, one switch being provided for each unit and the windings of relays B etc. are similarly connected to switches 232. With the switches 22M and 232 set as indicated in the figure, automatic control circuits as hereinafter described are established. Each of the switches 23! and 222 has an upper dead contact so that setting the switch on its upper contact disconnects the associated relay A, etc. or B etc. and the plate cylinder or impression cylinder controlled thereby will remain tripped on, unless tripped off by emergency or reverse tripping circuits, later described, which trip off all units. Setting a switch 234 or 232 in its lowermost position connects the winding of the associated relay A etc. or B etc. directly across lines L and L so that the plate or impression cylinder controlled thereby will trip oil and remain tripped off until the setting of the switch in question is changed.

Assuming the switches 23i and 232 to be set on their middle contacts, as shown in Figure 7, a connection for each unit is established to a rotary controller of the type shown in the Horton and This controller comprises a rotary member running in synchronism with the printing press and carrying a number of switch operating elements 235, which cooperate with sequential trip control switches S, S S and S If a sheet is rejected an appropriate element 235 will be set in an outward position so as to operate the switches S etc. as it passes by them. When sheets are accepted, however, the elements 235 will be set in an inward position, or nonoperating position. It will be understood that the elements 235 are operated as in the Horton and Eckhard patent so that the time of passage of an element 235 past the switches S etc. is synchronized with the movement of a gripper bar through the machine for successively tripping ofi" the units if the gripper bar carries no sheet or for successively tripping on the units if the gripper bar carries a sheet. One side of each of the switches S etc. is connected to a line 236 leading to the power line L The other side of switch S is conected to a line 231 to which the center contacts of switches 23l and 232 of the first unit are connected. Line 231 is also connected to the lowermost contacts of selector switches E E E etc.

The center conatct of switch 231, second unit, is similarly connected to a line 238, which leads to the switch S The center contact of switch 232 of the second unit is not, however, connected directly to this line but a connection path thereto may be established through line 239 and switches C and D provided these switches are in the position of the figure. Line 238 continues, and is connected to the second lowest contact of selector switches E E and E Similarly, the center contact of switch 23! of the third unit is connected to a line 249 which leads to switch S of the rotary controller. This line is connected to the third contact of switch E and E as. indicated and connection to line 240 of the center contact of the switch 232 of the third unit may be established through a line 24! and switches C and D provided these switches are in the position on the figure.

The switches E E etc. are utilized for selecting the unit which is to control the preliminary trippin of later units. With these switches set as shown in the figure, such control will be exercised by the first unit and the operation with the switches thus set will now be described. The switches C C etc. associated with the plate cylinder trip shafts of the units will occupy the position shown in Figure 7 when the plate cylinders are tripped on, and these switches will make contact in their lower position when the plate cylinders are tripped oil so as to connect lines 239 and 2M through lines 25!].and 25| with the switches E E The switches D D etc. will be closed, as shown in the figure, when the corresponding impression cylinders are tripped on but will be open when their associated impression cylinder trip shafts H are turned clockwise into their tripped off positions.

It will be assumed, in the first instance, that the press is out of operation and that all switch operating elements 235 of the rotary controller are set to trip off by closing the switches S etc. as they pass by them, and that all plate and impression cylinders are tripped off. Switches D 3D etc. will then be open, While switches C C etc. will be in their lower positions connecting lines 239 and 2-H to switches E E etc. Under these conditions the impression cylinder solenoid control relays A, A and A will be controlled by the respective switches S, S and S by virtue of the connections established through lines 231, 233 and 240. However, the plate cylinder solenoid'control relays B, B and B will all be controlled from line 23! leading to switch S, the connection for relay B being established through switch .0

gar-5, 393

line 239, switch C line 250 and switch E and the connection for relay B being established through line 241, switch C line 25l and switch E When a switch control element 235 which has been set in non-operating position by reason of the acceptance of a sheet passes switch 3, switch S will remain open so that the plate and impression cylinders of the first unit will be set to trip on at the proper point in the rotation cycle of that unit, by virtue of relays -A' and B not being energized. Similarly; the plate cylinders of units 11 and'III will trip on prematurely during the same cycle as the plate cylinder of the first unit trips on. The impression cylinders for the second and third units will, however, remain tripped off by reason of the fact that relays A and A will be energized by switch control "elements 235, which are still in the sheet rejecting and switch operating position, closing switches S and "S During the same cycle the tripping on of the plate cylinder of the second unit moves switch C into the position of Figure 7. Switch D being still open, the plate cylinder of the :secondunit remains tripped off. If the next sheet is accepted the next switch control element 235 in order on the rotary controller will also be set in non-operating position. When this element reaches switch S, switch S will not be closed so that unit number .1 remains tripped on. At the same time the immediately preceding switch control element 235 will be opposite switch S? so that this switch also willremain open and the impression cylinder for the second unitywill trip on while the plate cylinder will remain tripped on. It will be recalled that during the first cycle discussed the plate cylinders for all units were tripped on so that switch and any later corresponding switches were moved to the upper position, or position of Figure 7, at about the same time as Switch D and any later similar switches, however, remained open so that tripping off of the plate cylinders for the second and any later units by rotary controller switch S and any later rotary controller switches was prevented- The tripping on of the second unit impression during the second cycle will now, however, have restored switch D to the position of the figure so that'th second unit is under full Control by rotary eontroue'rswitcnsa. HOW- ever, the switch control element 235 to reach switch S during the third cycle of dp'muen will be the second such element which was set to non-operating position so that switch S will remain open with the result that the piers and impression of the second unit remamtfipped on. By the means just discussed, the plate cylinder of the second unit is tripped on prematurely by one operating 'cycle'of that unit while the plate cylinder of the third unit is tripped on prematurely by two operating cycles, etc. "While the elements of a fourth unitare not shownin Figure '7, a line 242 leading thereto from switch S and a selector switch E are shown, so that the manner of adding aiourthorariy' desired number of units will be obvious.

If it is desired to comm the ribing by alater unit the switches E2, etc; are

reset. For example, setting each of these switches up one contact willconnect the lines 250 and 251 and any further similar lines of laterunits to line 2-38 leading to; rotary controller switch S The result of this will be that the first unit will trip on .undercontrol of switch S as before; During-this operating-cycle the later units will remain tripped off by reason of the fact that relays A and A will "be energized through lines 238 and 240 while relays B and B will both be energized from line 238 and switch S through switches E and C and E and 0 respectively. The tripping on of the second unit will reset switches C and D into the position of Figure 7, so that the third unit plate will trip on prematurely but the third unit impression will not trip on until the non-operating switch control element 235 reaches switch S at which time the third unit will be set to trip on. Any later unit plate cylinder will trip on prematurely during the same cycle as the third unit plate cylinder.

Setting the switches E E etc. one contact higher will result in the first, second and third units tripping on normally while the 'fourth and any later units will trip on prematurely as described.

Once the press is in operation, all switches C etc. and D etc. will be in the position of the figure, so that each unit is under control of its own rotary controller switch. As soon as a sheet is rejected, and a switch controller element 235 is therefore setin switch operating position, the successive units will trip off one after another as this switch controller element reaches the corresponding switches S etc. This action occurs in the following way: During'the first cycle switch S closes, energizing relays A and B and setting the first unit to trip off. During the next cycle this trip control element operates switch s opening switch D and setting switch C on the lower contact. A similar action occurs for the third and later units in sequence. This action is not afiected by the setting of the switches E E etc., for premature plate cyl-- inder tripping under control of the first, second or later units, since the impression and plate for each unit will always be tripped on" by the rotary controller switch associated with that unit.

Means is provided for tripping ofi all units simultaneously under certain conditions, and is also shown in Figure 7. This means comprises a relay R one end of the winding of which is con nected through a line 260 to the power line L", While the other end of the winding is connected through lines 28'! and 262 to a contact of the relay R An alternate connection path to another contact of relay B may be established through pushbutton switches P and P and line 253; A maintaining circ'uitfor relay R. is provided, through line 264, a pair of the relay contacts, and line 265 connecting through pushbutton P to the line 263 previously referred to. The relay R is a reversing relayfor the press and is controlled by reverse pushbuttor'i P If the reverse button P is not pressed for reversing the printing press, connection between line 263 and" line L is established through contacts of the relay R and lines 266 and 236. Pressing the emergency trip button P will thus energize relay B." through line 26L pushbuttons' P and P and lines 253, 266 and 236 leading" to power line L The relay once energized will remain energized by reason of the closing of its contactscqnnecting the maintaining circuit uses Z'G l'and 255,

7 until the releasebutton P is pushed to open the circuit. The energizing of relay R connects each of lines 21mm, 212, 213', m and 275 with me 265 and thus through the circuit previously traced to power nne so that an or the tests A, etc. and B1, etc. are energized, tripping of f mini 19'? pression andfplate cylinders. Pushing the emer:- gency trip button release P breaks the maintaining circuit of relay R, thus deenergizing the relays A, B etc. and restoring the control circuit as previously described. The circuit also provides for automatic tripping ofi of all impression and plate cylinders upon reversal of the press. Pushing the reverse button P will energize the relay R breaking the connection between lines 263 and 266, but establishing connection between lines 266 and line 262 which bypasses the push buttons P and P so that when the reversing relay R is energized all units will be tripped ofi.

Comparison of the embodiment of Figures 1 to 5 with that of Figures 6 and 7 While the embodiment of Figures 6 and 7 discloses the operation of the trip control mechanism by a rotary controller, it will be apparent that the same circuits can be utilized in a press utilizing control by means of the gripper bars or other sheet carrying elements. All that would be necessary to effect this modification would be to substitute for the rotary controller switches S,

etc., similar switches operated by shoes 56 at the Various units as described in connection with the embodiment of Figures 1 to 5, such shoes being suitably located for the proper timing of the action.

It will also be observed that most of the mechanism of Figures 1 to 5 is replaced by mechanism producing similar results in Figures 6 and 7. For example, theselector switches E E etc. perform similar functions to the handles I20 and I32 by which the point in the line of units at which the premature tripping will commence is determined. The switches 23! and 232 provide for manually setting on a given plate or impression cylinder in either tripped on or tripped off relation regardless of the operation of the remainder of the press and thus perform the functions of the man ually operated mechanical elements heretofore provided in a machine of the type such as shown in Figures 1 to 5. Relay R and pushbutton P perform a similar function to the rod I40 and handle I42. A quicker tripping off action in case i of emergency may, however, be obtained, since in the embodiment of Figures 6 and 7 it is possible for the plate cylinder to trip off in advance of the impression cylinder, while in the embodi- 1 ment of previous figures, the tripping off of the plate cylinder will always follow the tripping off of the impression cylinder and must wait until this has occurred. The pushbutton P reversing relay R. and relay R perform similar functions to the reversing trip off pawl I60 and associated apparatus. Here again, however, the actual tripping off of the units may occur sooner for the same reasons as pointed out in connection with the emergency tripping ofi. Provision for silencing the preliminary plate cylinder tripping mechanism for any unit is made by means of the switch E etc., for setting any one of these on its uppermost contact subjects the corresponding unit to control only by its own rotary controller S2, etc.

as the case may be. In this way, provision is made for a similar action to that obtained by means of silencing handles I53.

The embodiment of Figures 6 and '7 possesses the advantage of flexibility and simplicity'w'hich are often inherent in electrical control systems as distinguished from mechanical systems. For example, a unit equipped with the double solenoid control of Figure 6 may be adapted for different normal tripping'cycles by merely rewiring its control circuits. Sucha unit is capable of tripping a plate cylinder on in advance'of the.

The embodiment of Figure 8 Still another form of the invention is shown in the circuit diagramof Figure 8. In the form of Figures 1 to 5 inclusive, the sequential tripping of the units was controlled by means associated with the sheet carrying means. In the form shown in Figures 6 and 7 sequential trip controlling was accomplished by means of a rotary controller driven in synchronism with the press. In the form of Figure 8 the sequential tripping of the units is controlled by the units themselves, the tripping off of one unit setting the following unit to trip off, and so on.

The mechanical elements of the tripping mechanism for the units may be the same as in the embodiment of Figures 6 and 7 and may be controlled by similar solenoids and relays. In/ the circuit of Figure 8, accordingly, the same solenoids 210 and 220 and control relays A A and B B are indicated. The arrangements shown for emergency tripping off of the units are likewise the same, as also are the control switches 23| and 232.

Switches operated by the plate cylinder and impression cylinder trip shafts in a manner similar to the switches C etc. and D etc. are again provided. A switch d operated by the impression cylinder trip shaft I! of the first unit is provided as well as a switch d and switch 0 operated respectively by the impression and plate cylinder trip shaft of the second unit.

The sequential tripping according to whether sheets are accepted or rejected in the registering unit is conveniently initiated by the stripping shaft N5 of the registering unit, previously described in connection with Figures 1 to 5, the stripper element I I6 being utilized to operate a control switch 300. If a sheet is accepted, so that the stripper H6 is in its counterclockwise position, switch 300 will be opened, while if the stripper H6 is in its clockwise position for rejection of the sheet, the switch 300 will be closed.

Switch 300 is connected to switches 23| and 232 of the first unit for controlling the relays A and B. Accordingly closing of switch 300 when a sheet is rejected sets the first unit to trip off, while opening switch 300 sets this unit to trip on.

Assuming both units shown in Figure 8 to be tripped on, which is a condition corresponding to the switch positions shown, the rejection of a sheet will close switch 300, which sets the first unit to trip off. When the impression cylinder of this unit trips offfswitch d shifts to its'lower position, connecting line 303 leading to the second unit to power line L through a line 30'2.' This sets the second 'unit to trip off, relay A being energized through a line 304, and relay B being energized through switches d 0 and a line 305. When the second unit impression trips off, switch d shifts to its lower'pos'ition energizing a line 309 leading to the third each unit, in turn, to trip off. Switch 0 also shifts to its lower position, thus connecting relay B to selector switch E Assuming both units to be tripped 01f, with switches d, d and c in their lower positions," and that a sheet is accepted so that switch 300 5 opens, relays-A and B-'-will be deenergized, -set--' unit, if any, forsetting ting the first unit to trip on. At the same time, plate cylinder trip relay B which is connected to line 301 through switches c and E will also be deenergized, setting the plate cylinder tripping mechanism of the first unit to trip on during the same cycle. The second unit impression will remain set for tripping off during this cycle,'since a connection for energizing relay A is maintained through switch d until the impression of the first unit trips on, restoring the switch 11 to the position of the figure and thus deenergizing relay A to set the impression trip mechanism of the second unit to trip on during the next cycle. At the time when the plate cylinder of the second unit tripped on, switch (2 returned to the position of the figure, but no connection was established for energizing relay B by reason of the switch d being still in its lower position. As the impression for the second unit trips on, switch d returns to the position of the figure, but line 303 is now dead, by reason of the previous return of switch d.

If selector switch E is set on the upper contact, and it be assumed that both units are tripped off, the action upon acceptance of a sheet will be the same as before described, except that relay B being controlled from line 307 will be energized during the first cycle, through line 3 2, 5

switch d, line 303, line 301, switches E '0 and line 305. The plate cylinder for the second unit will, therefore, not trip on prematurely.

The manner of adding units will be apparent from Figure 8 and the foregoing description, each added unit having a selector switch E etc. and switches 0 11 etc.

What is claimed is:

1. In a multicolor oilset press having a plurality of printing units for printing in predetermined sequence on a sheet, and each of which comprises plate, blanket and impression cylinders, an ink motion and a unit tripping mechanism for tripping the plate, impression and ink motion off in predetermined order and in timed relation to the rotation of the impression cylinder, and for tripping the plate, impression and ink motion on in the same predetermined order and timed relation, and in combination, a sequential trip control for operating the unit tripping mechanisms of the units in the said predetermined sequence, and further plate trip control means operated by the sequential trip control for tripping on the plate of a unit during a rotation of the impression cylinder preceding the rotation in which the first said unit tripping mechanism is operated by the sequential trip control in the said predetermined sequence to trip on the impression and ink motion.

2. In a multicolor offset press having a plurality of printing units for printing in predetermined sequence on a sheet, and each of which comprises plate, blanket and impression cylinders, an ink motion and a unit tripping mechanism for tripping the plate, impression and ink motion off in predetermined order and in timed relation to the rotation of the impression cylinder, and for tripping the plate, impression and ink motion on in the same predetermined order and timed relation, and in combination, a sequential trip control for operating the unit tripping mechanisms of the units in the said predetermined of adjacent units for advance tripping on of 22 sequence, and further plate trip control means for a group ofsuccessive units, and operated by the sequential trip control, for tripping on the plate of the'first unit of the group during a rotation of its impression cylinder preceding therotation in which the first said unit tripping mechanism is operated by the sequential trip control in the said predetermined sequence, to trip on its impression and ink motion, and for tripping on the plate of each succeeding unit of the group in advance of its impression and ink mechanism by one more rotation of its impression cylinder than in the case of the preceding unit.

3. The combination according to claim 2, in which the said further plate trip control means is adjustable to select any of a plurality of groups their plates.

4. The, combination according to claim 3, in which means is provided for silencing the further plate trip control means for a selected unit.

5. In a multicolor offset press having a plurality of printing units for printing in predetermined sequence on a sheet, and each of which comprises plate, blanket and impressioncylinders, an ink motion and a unit tripping mechanism for tripping the plate, impression and ink motion off in predetermined order and in timed relation to the rotation of the impression cylinder, and for trippin the plate, impression and ink motion on in the same predetermined order and timed relation, and in combination, a sequential trip control for operating the unit tripping mechanisms of the units in the said predetermined sequence, and further plate trip control means comprising means, controlled by the tripping on of a unit by the said sequential trip control, for tripping on the plate of a succeeding unit at substantially the same time as the plate of the first said unit.

6. The combination according to claim 5, in

which the said further plate trip control means is ALEXANDER J. ALBRECHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,874,013 Kaddeland Aug. 30, 1932 1,878,904 Smith Sept. 20, 1932 2,205,720 Goebel et a1. June 25, 1940 2,231,914 Huck Feb. 18, 1941 1 2,335,010 Huck Nov. 23, 1943 2,335,954 Neal Dec. '7, 1948 2,356,058 Hunting Aug. 15, 1944 2,419,403 Horton et a1. Apr. 22, 1947 

